Bangladesh has been recognized for its great success in improving educational and health outcomes during the past few decades. With its Early Years Preschool Program, Save the Children has been providing an additional year of preschool to four-year-old children, who then progress to the one-year government preprimary class at age five and to first grade at age six. AIR is investigating the impacts of offering this additional year of preschool education in Bangladesh on child development outcomes (cognitive and social emotional), and will examine the benefits relative to the costs of the program.